if you’re not on twitter, and even if you are, you may have missed this. in response to social anthropologist a.j. west’s post ‘HBD’, misdreavus has pretty much completely — and valiantly! — explained ALL of the whys and wherefores of human biodiversity in just six short paragraphs.

if you’re on twitter and not following misdreavus, you should be! and if you’re not on twitter, you should get on twitter JUST to follow misdreavus! (^_^)

his comments @west’s blog start here. i’ve only cut-and-pasted some of them here — there’s more on west’s blog. much more. you should definitely head over there and read them all!

note that misdreavus never mentions that hbd is a political or social or ideological movement. THAT’S BECAUSE IT’S NOT! (all emphases are misdreavus’ — except for the all caps in the previous sentence. yes, that was me SHOUTING! (*^_^*) )

“The scientific basis behind so-called ‘human biodiversity’ (or HBD) is blessedly simple in its obviousness, albeit one that goes shockingly under-acknowledged by most who call themselves authorities in the human sciences. We already have enough evidence that genetic variation in the human species must account, in some non-trivial way, for the variation in phenotypic diversity we see among the major extant human populations living today. By that I refer not only to salient differences such as the height gap between Aka Pygmies and Congolese Bantus, or that fact that west Africans have more prognathous jaws than northern Europeans, but also artifacts of our biochemistry such as Type II diabetes (which usually correlates with obesity) or alcohol metabolism (a large percentage of east Asians have abtabuse built into their genomes — Greenland Inuits don’t). Of course. We get it. There is inter-ethnic (or inter-demic, or inter-population — feel free to choose whatever taxonomic subdivision *du jour* is fashionable these days among the PC crowd) variation for virtually every single trait for which there exists variation among members of a single ethnic group: no two Irishmen have noses that are exactly the same shape, and neither do any two races, on average. No two Koreans have skin color that is exactly the same hue, and there is a vast gap in skin color between Norwegians and Dinka. No two Russians are of exactly the same height — not even identical twins, and virtually every single Swede is taller than every single Mbuti pygmy. This much is obvious to anyone with an unimpaired frontal lobe.

“And we can extend this reasoning not only to the aforementioned physical traits (and much more), but also cognitive skills, however they are defined in every single culture — for virtually every single behavioral trait *ever* documented among human beings is heritable. We know that two children who are reared by the same pair of parents can be *strikingly* different in their behavior and temperament, and that these differences almost always persist long past childhood. It matters not how ‘personality’ and ‘temperament’ are defined, or that there are not, never have been, and likely never will be any precise definitions of these terms that are useful to psychological science. (Let us avail ourselves of the postmodernist obscurantism, trenchant reality denial, and casual know-nothingness that you decried earlier in a post about social anthropology. It is enough for us to acknowledge that no two humans are alike in behavior, and that the human mind is not a blank slate.) Behavioral differences between any two people, even identical twins, manifest themselves starting from birth, and they only magnify throughout the lifespan. Not surprisingly, it has been demonstrated that babies from different ethnic groups also demonstrate behavioral differences from the cradle. East Asian babies, on average, tend to remain placid and calm when a soft cloth is dropped over their faces — west African and European babies are the polar opposite. See here.

“If, indeed, it is the case that human beings vary in behavior, and if it has been proven that much of this variation in behavior may be attributed to hereditary causes, then *this alone is sufficient to demonstrate that heredity must explain some of the variation in cognition between any two human populations who vary in their evolutionary history*. Well, has this been proven? Of course it has. ‘Heritability’, as the term is implemented in quantitative genetics, refers to the portion of variation in a phenotype within a population that may be attributed to heritable differences, given a certain range of genotypes and phenotypes: H^2 = Var(G)/Var(P). The classical twin study, as much as it is ballyhooed by idiots in the social sciences who are reality-averse, has provided heritability estimates for a wide array of psychological dimensions ranging from IQ and its subscores (visuospatial, verbal, mathematical, etc.), to reaction time, to the ‘big 5′ (e.g. extraversion/intraversion, neuroticism, etc.), to all psychiatric disorders (e.g. autism, schizophrenia), to what brand of cereal you prefer in the morning, and much more. In virtually all cases, these heritability estimates are higher than zero — often substantially higher than zero. They are not only consistent with studies of identical twins reared apart, but also longitudinal adoption studies: studies with sample sizes ranging in the multiple thousands have demonstrated consistently that adopted children, even when adopted during early infancy, resemble their biological parents to a vastly higher degree than they resemble the adults who actually raised them (i.e. ‘adoptive’ parents).

“And one of the most common, and in fact the overarching application of heritability estimates is evolution. Heritability estimates tell you precisely how much a trait will change in a population, over time, as a response to selection. In other words, if the smallest 25% of all cattle in a herd failed to reproduce every generation, how much would you expect that trait to increase over time? Given even modest selection on any trait from height, to violence, to ‘visuospatial IQ’, to extroversion, and much more — just about how much heritable variation would you expect see between the disparate human populations on Earth since the time we migrated out of east Africa?

“The answer is obvious. if you have read ‘The 10,000 Year Explosion’ by Cochran and Harpending (which I’m not sure you have), the authors provide ample evidence that substantial heritable change is possible in the relative blink of an eye — hundreds or thousands of years, not just tens of thousands. (Evolutionarily speaking, of course.) It is a trivial matter to ensure that a population, twenty generations from now, will be on average as bright as the brightest 2% within that population today. Today’s Scandinavians are not yesterday’s Vikings. Han Chinese in Sichuan Province today are not genetically exchangeable with Chinese during the reign of the first Qin Emperor. Swedes are not Norwegians, Egyptian Copts are not Muslims, and Hejazi Arabs are not Najdi Arabs. I could belabor this point ad nauseam, but I believe I have made my point sufficiently clear.

“Of course, this is not to say that all of the variation in behavior you see among human beings is hereditary in origin. Nobody ever claimed that — a heritability estimate below 1.0 proves some source of variation that is exogenous to the germ plasm, or perhaps a statistical artifact that is generated in the process of (imperfectly) measuring the trait in question.”

(^_^)

_____

the big m also had something to say about the ideas tossed around on this blog (thanks, misdreavus!). i’m thinking i’m gonna just hand the reigns over to him, because he’s summarized the theory (with a small “t”) better than i can! (~_^)

“You also misrepresent some of the basic claims of some of the bloggers in the HBD sphere. HBD-chick, for one, who does a lot of blogging about consanguineous marriages and its implications for human evolution. You claim:

“‘That account also makes bizarre claims, like the idea that altruism is greater in societies that have complex marriage systems and that ‘marry out’ of the family unit – because, apparently, when you marry out of your circle for generation after generation, everyone you meet is almost guaranteed to be your relative and therefore worthier of compassion!’

“No. The point is that human populations vary considerably, throughout the ages, in the *degree and prevalence of consanguineous marriages*, and that basic arithmetic would show you that this will increase the relatedness of two members within an extended family beyond what may be expected from random mating. The Gulf Arabs have been marrying their cousins for *centuries*, and this practice possibly dates earlier than the prophet Muhammad — Norwegians and Danes *haven’t*. This means that Saudis, on average, are much more inbred than your typical northern European, and that this difference can be measured through segments of DNA that are ‘IBD’ (identical by descent) — Arabs share a lot more of these than ethnic groups where cousin marriage is taboo.

“The coefficients of relatedness work somewhat like this: normally, your brother shares half of your DNA that is identical by descent, as do your biological parents. Your nieces and nephews share 1/4. Your cousins share 1/8. So on, and so forth. Hamilton’s laws demonstrate altruism (e.g. reducing your own fitness, on the behalf of someone other than yourself) can boost an organism’s fitness, on average, if the recipient of the altruism increases *its fitness* in a way that is commensurate with the relatedness of the altruist and the recipient. In other words, r = B > c.

“Imagine that by sacrificing your life to save your brother who is drowning, you thereby ensure that your brother would have three additional children that he would not have otherwise had, had he been permitted to sink (and drown). On average, this would ensure a net benefit of fitness for yourself, despite the fact that you have totally abandoned the carrier of your genes (your body) by sacrificing yourself on behalf of your brother. Why? Because 3 multipled by 1/2 (the fraction of genes that your brother, on average, shares in common with you) is greater than 1. You will have increased your contribution to the gene pool. And any alleles that promote such an altruistic behavior on behalf of a person, for his blood relatives, should increase in frequency through selection. This is especially the case for populations that have been inbreeding throughout the ages — because brothers, in this circumstance, are more related to each other than ordinary brothers.

“The idea is that this sort of consanguinity would increase the fitness rewards for altruism *on behalf of blood relatives* to an unusually high degree that is absent among populations that have been out-breeding. In other words, it increases the odds of nepotism, clannishness, and feuding between clans, among other anti-social behaviors that make a civil society very difficult, among other destructive consequences. (Without peeking, who is more likely to help his brother cheat on a standardized test to qualify for a job — the average Najdi Arab, or the average Finn?)

“For societies that have been deliberately *outbreeding*, the exact opposite scenario occurs — distant relatives, whether you realize it consciously or not, are more related to you than they would be in a society with perfectly random mating, and hence you see higher levels of the low-degree altruism that makes the sort of society you see in Woebegon Lake or Sweden possible. The idea is that Swedes are much more willing to sacrifice their fitness in a modest way on behalf of complete strangers who are members of their ethnic group, e.g. by paying higher taxes, and that this tendency has been selected for since the introduction of Christianity during the medieval era, which forbade consanguineous marriages throughout much of western Europe. Like I said earlier. You only need hundreds of years to see a noticeable change.

“If you remain skeptical of this theory, all is fine, but let me tell you something — it does a decent job explaining why the Swedish welfare state works perfectly fine for Scandinavians, but results in utter dysfunction for Somali refugees. It explains why democracy persistently fails in certain parts of the world, despite billions of dollars spent on aid, foreign advisers, and the best advice of seasoned policymakers — some people don’t give a damn about people outside their extended family, and you can’t change that. It explains why there is a west-east cline in Europe for corruption, social trust, and civic mindedness, inasmuch as they can be measured by political scientists — Ukrainians are much more corrupt than the Norwegians, and they’ve been this way for a long time. It does NOT say that all human behavior is genetically mediated, or that altruism is automatically greater in societies were people have been marrying unrelated persons.”

everyone should be skeptical of this theory! i am. (or, at least, i try to keep reminding myself to be. (~_^) )